Radon

Radon is a tool for Python that computes various metrics from the source code. Radon can compute

• McCabe's complexity, i.e. cyclomatic complexity
• raw metrics (these include SLOC, comment lines, blank lines, &c.)
• Halstead metrics (all of them)
• Maintainability Index (the one used in Visual Studio)

Requirements

Radon will run from Python 2.6 to Python 3.3 (endpoints inclusive) with a single code base and without the need of tools like 2to3 or six. It can also run on PyPy without any problems (version tested: 1.9 and 2.0.0).

Radon does not depend on any other Python package.

Installation

With Pip:

$ pip install radon

Or download the source and run the setup file:

$ python setup.py install

Usage

Radon can be used either from the command line or programmatically. Documentation is WIP at https://radon.readthedocs.org/.

Cyclomatic Complexity Example

Quick example:

$ radon cc -anc ../baker/baker.py
../baker/baker.py
    M 581:4 Baker.parse_args - D
    M 723:4 Baker.parse - D
    M 223:4 Baker.command - C
    M 796:4 Baker.apply - C
    M 857:4 Baker.run - C

32 blocks (classes, functions, methods) analyzed.
Average complexity: B (6.15625)

Explanation:

• cc is the radon command
• -a tells radon to calculate the average complexity at the end
• -nc tells radon to print only results with a complexity rank of C or worse. Other examples: -na (from A to F), or -nd (from D to F).

Actually it's even better: it's got colors!

Links

• Documentation: https://radon.readthedocs.org
• PyPI: http://pypi.python.org/pypi/radon